Integrated circuits (ICs) are designed to include active and passive elements such as transistors, diodes, resistors, and capacitors that are interconnected in a predetermined pattern to perform desired functions. Integrated circuits and assemblies have become more complex with time. In a logic circuit, the number of integrated circuit logic units and interconnects on a given size die have been substantially increased reflecting improved semiconductor processing technology. Integrated circuits can include, for example, powerful application specific integrated circuit (ASIC) devices designed to provide a high degree of functionality for a particular device or type of application.
ASIC's are produced as logic chips designed to perform a specific function and thereby meet the specific needs of a specific application. The designs are implemented in a single silicon die by mapping functions to a set of predesigned, preverified logic circuits provided by an ASIC vendor. These circuits range from simple functions, such as inverters, NANDs, NORs, flip-flops and latches, to more complex structures such as memory arrays, adders, counters, and phase-lock loops.
Integrated circuits can also include gate arrays having transistors arrayed in rows and columns on each die. Standard processing to make such structures includes fabricating as many as a half a million transistors comprising a quarter of a million gates per die. Each transistor is provided with conductive contact points that can also be arranged in rows and columns. After subsequent processing steps, including, for example, adding conductive layers, are performed, the completed die is tested. In some circumstances, if any of the devices on the die are defective, that die will fail an exhaustive test and be scrapped. Alternatively, functional repairs are performed either by using conductive material and spare gates to reconnect non-functional logic or the die is reprocessed by adding all the required additional semiconductor and conductor layers to replace or repair the non-functional portion. All of these approaches consume significant time and financial resources.
Thus, a heretofore-unaddressed need exists in the industry to address the aforementioned, and other, deficiencies and inadequacies.